I'm not a pro, but you do want to pipe that T&P over the drain (leave a couple inch gap between the pipe and the drain). Few things to remember:
- pipe must stay full diameter (3/4") and not be reduced
- no valves/tees placed on the line
- no threads on the end of the pipe
- must run level or down, but never up
Most places will not let you run it to the drip pan as teh drip pans is not made to handle the flow of the T&P. It would quickly overflow if the vavle ever lifted.
If the floor drain seems to work okay with no smells, then I would say it is probably in good shape. If you do get smells (maybe in the winter since the A/C is off and the trap may start to dry out), just poor some water down the drain and the smell should go away.
What are your plans for flooring? Probably vinyl of maybe tile would be good since it is a potentially wet area.